Output current 12V-40A/ 24V-20A, Input voltage 130V-250V, Color Silver, Input cable 110cm, Material Metal case, Charging current 40000mA, Size 180x145x70mm/7.1×5.7×2.8in, Applicable voltage DC 12V/24V, Scope of application Lead-acid battery / maintenance-free battery / dry battery water battery (non-rechargeable lithium battery), Rated power 400W, Model AJ-618A.
Just check coupons out (with price alert and history). What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in Europe 
. I don’t want to misguide you about the price. I don’t know if it’s good, because I don’t have enough records in my database…
Link: Banggood product page
1. ($41.85): Cuponation9
2. ($41.85): 9OFFSUMMER
3. ($42.31): hoNEYbGdeAlS
4. ($43.23): BG00c906
coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): MVC8SPRING, 8BGwbg2204, 2203ActiesNL, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN
(these coupons are old, so probably won’t work)
Price history and price alert
Price history is not available for this item (not enough database records)! The lowest price was $37.99 though.
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).